ConeGenerator.cs

using System;
using System.Linq;
using UnityEngine;

public class ConeGenerator : ShapeGenerator
{
    #region InspectorVariables
    [Header("Cone values")]
    [Range(0, 100)] public float bottomRadius = 1f;
    [Range(0, 100)] public float topRadius = 0f;
    public Vector3 topPosition = new Vector3(0, 1f, 0);

    [Header("Technical")]
    [Range(3, 1000)]
    public int sideCount = 500;
    #endregion InspectorVariables

    #region Implementation
    protected override (Vector3[] vertices, int[] triangles) GenerateTopology()
    {
        Vector3[] top_circle = new[] { topPosition };
        Vector3[] bottom_circle = new[] { Vector3.zero };

        int[] top_boundary = new int[] { 0 };
        int[] bottom_boundary = new int[] { 0 };

        if (topRadius > 0f)
        {
            Vector3[] edge = GetCirclePoints(topRadius, sideCount, topPosition);
            top_circle = top_circle
                .AppendRange(edge)
                .Append(edge[0])
                .ToArray();

            top_boundary = Enumerable.Range(1, edge.Length).ToArray();
        }
        if (bottomRadius > 0f)
        {
            Vector3[] edge = GetCirclePoints(bottomRadius, sideCount);
            bottom_circle = bottom_circle
                .AppendRange(edge)
                .Append(edge[0])
                .ToArray();

            bottom_boundary = Enumerable.Range(1, edge.Length).ToArray();
        }

        return CreatePrism(
                    CreatePlane(top_circle),
                    CreatePlane(bottom_circle, true),
                    top_boundary,
                    bottom_boundary
                );
    }
    #endregion Implementation
}